Self-sensing piezoelectric composites via generation and reception of ultrasonic guided waves

This paper presents a novel family of intelligent piezoelectric composite structures for establishing structural self-awareness via integrating the function of load bearing with the capability of generating and receiving high frequency, single-mode mechanical waves. Unlike conventional self-sensing composites limited to passive monitoring and low actuation capacity, this study introduces a novel structure-actuator-sensor integration that demonstrates active sensing and wave mode control capabilities, while preserving its mechanical performances. The structure is formed by distributing Pb(Zr_0.52Ti_0.48)O₃ piezo powder and epoxy as the active component to impregnate glass fibers, enabling every inch of the material to function as both an actuator and a sensor. Firstly, piezoelectric composite plate specimens are crafted to achieve high degree of sensitivity and reliability through material parameter optimization and process refinement. A series of mechanical performance comparative experiments are conducted to verify the load-bearing competency of the composites. The active actuation and self-sensing functionality of the composites are investigated via numerical simulations and experimental demonstrations. Single-mode guided wave propagation is successfully achieved. It enables the reduction of signal processing complexity caused by multi-modal and dispersive nature of guided waves, a common challenge in structural health monitoring systems. The simulations and experiments showcase that the proposed composites successfully achieve the active damage detection via single mode guided wave generation and reception. The composite system possesses the prowess for achieving active self-awareness through such a new fashion actuator-sensor-structure integration, which could be potentially utilized in the next generation of wing and fuselage structures in aviation industry, high pressure vessels for hydrogen storage, and smart composite pipelines for transporting gas and petroleum. The paper finishes with summary, concluding remarks, and suggestions for future work.